[llvm] [AMDGPU] Skip register uses in AMDGPUResourceUsageAnalysis (PR #133242)

[Nicolai Hähnle via llvm-commits]

https://github.com/nhaehnle approved this pull request.

I agree with @Flakebi that for entry functions it's better to report what the HW initializes.

https://github.com/llvm/llvm-project/pull/133242